In electric vehicles, as in traditional vehicles, maintaining control over the angular speed of the wheels is critical to maintaining traction with the road surface. A loss of traction can occur from excessive acceleration or deceleration (i.e. hard braking). When accelerating, the wheels can receive excessive torque from the electric motor. This causes a loss of traction with the road surface and wheel spin. Similarly, when the wheels receive excessive braking force, the wheels lose traction with the road surface. Modern vehicle systems strive to eliminate a loss of traction and wheel spin with wheel stability control systems. These systems include, for example, antilock braking, traction control, and stability control.
Wheel stability control systems are limited in effectiveness by the ability of the vehicle's sensors to determine the vehicle's behavior. In some situations, the vehicle's sensors provide inaccurate or misleading information about the vehicle's behavior. This situation can arise even when the sensors are performing their function correctly and accurately. For example, a wheel angular speed sensor may be correctly detecting the wheel's angular speed, but if the wheel is not maintaining traction with the road surface, the information inaccurately describes the vehicle's speed. Inaccurate information about the vehicle can cause the wheel stability control systems to underperform. Therefore, systems and methods for gathering accurate information about a vehicle and using this information in modern control systems are highly desired.